In our copending U.S. patent application Ser. No. 07/471,882, filed Jan. 29, 1990, now abandoned, the disclosure of which is expressly incorporated herein, we disclosed a novel group of compounds, which can be generally described as ethylenically unsaturated carboxy esters, which are effective dentin conditioners useful for treating the dentin of a tooth prior to use of a bonding resin and/or restorative composite. As disclosed in said application, the dentin conditioner causes a substantial increase in the strength of the bond between the dentin and the composite.
In accordance with the present invention, we have discovered a novel group of compounds to be used in conjunction with the dentin conditioner disclosed in our earlier application to further increase the bonding strength between dentin and a dental composite restorative material. In addition, the new compounds of the present invention can be used alone, i.e., without the dentin conditioners, to increase the bond strength between dental composites and metals used in dentistry for orthodontic brackets, metal frameworks in crowns and bridges, and the like.